JPWO2016194100A1 - Core discharging device and core discharging method - Google Patents

Abstract

The strength of the sand core is lowered by supplying a cooled humidified gas to the sand core formed with the binder containing water glass in the cast molding coarse material.

Description

  The present invention relates to a core discharging apparatus and a core discharging method, and more particularly, to a core discharging apparatus and a core discharging method that facilitate breakage of a core in a cast material coarse material.

  For casting of hollow products, etc., a sand core made of cast sand hardened with a binder is placed in the mold and the molten metal is supplied. By applying force, the sand core in the cast material coarse material is destroyed and discharged.

  As a binder for hardening the foundry sand, an organic binder using a phenol resin or the like, or an inorganic binder using water glass is known.

  As described above, in the method of applying an impact force to the cast material coarse material to break the sand core, the sand core is broken and gradually discharged from the sand discharge port by repeatedly applying the impact force. However, it is necessary to apply an impact force greater than a predetermined value for discharging the sand core. In addition, if the density of the cast sand remaining in the cast molding coarse material decreases with the discharge of the casting sand, voids are generated in the cast cast crude material and there is no support from the inside, so a constant impact force If repeatedly given, the cast product may be plastically deformed or broken.

  In Japanese Patent Application Laid-Open No. 7-314125 of Patent Document 1, after smashing a cast molding coarse material with a predetermined impact force and collapsing the sand core, it is struck with an impact force smaller than the impact force. Discharging the casting sand is disclosed.

  Japanese Patent Laid-Open No. 9-174194 of Patent Document 2 discloses that a sand core formed with a binder containing water glass is collapsed by immersing it in water after casting. Yes.

Japanese Unexamined Patent Publication No. 7-314125 Japanese Patent Laid-Open No. 9-174194

  However, in the thing of the said patent document 1, when the density of the casting sand which remains in a cast molding coarse material falls, the impact force transmitted to a sand core through a cast molding coarse material will become weak. End up.

  In particular, when the sand core uses an organic binder, in the vicinity of the surface in contact with the molten metal, the binder is easily decomposed and decomposed by heat during casting, but the resin remains in the sand core. As a result, the strength of the core is maintained.

  Therefore, it is difficult to completely destroy and discharge the inside of the sand core only by impact force, and it is necessary to apply heat that decomposes the organic binder at the center of the sand core.

  However, if the organic binder is held at a high temperature to thermally decompose, the cast product coarse material itself may be thermally deformed, particularly in a thin cast product coarse material such as a cylinder head. In addition, when the cast molded product coarse material has a large thickness difference, the temperature difference of the cast molded product coarse material becomes large during cooling, resulting in residual stress and cracking.

  Moreover, in the thing of the said patent document 2, since a cast molded article rough material is immersed in water, adjustment of a cooling rate is difficult, especially in the case of a thin-walled product, a crack arises by a residual stress. Sometimes. In addition, the water used for the core discharge treatment becomes strongly alkaline, necessitating a neutralization treatment, and the cost increases.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to facilitate the destruction of the sand core and to adjust the residual stress in the cast molded product coarse material. It is possible to provide a core discharging apparatus and a core discharging method capable of improving the strength of a molded product.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have supplied a humidified gas with added humidity to a sand core formed with a binder containing water glass. It has been found that the strength can be reduced and the above object can be achieved, and the present invention has been completed.

  That is, the core discharge device of the present invention is characterized by including a humidified gas supply device that supplies a humidified gas to a sand core containing a binder containing water glass in a cast molded product.

  Further, the core discharging method of the present invention has a humidified gas supply step of supplying a humidified gas to a sand core containing a binder containing water glass in a cast molded product to reduce the strength of the sand core. It is characterized by.

  According to the present invention, since the humidified gas is supplied to the sand core formed with the binder containing water glass, the sand core can be easily destroyed and the cooling rate of the cast molded product coarse material It is possible to improve the strength of the cast molded product rough material by the quenching effect while suppressing the occurrence of residual stress.

It is the schematic which shows an example of the core discharge apparatus of this invention.

The core discharging apparatus and the core discharging method of the present invention will be described in detail.
The present invention uses a sand core containing a binder, and the binder contains water glass. The water glass is cured by approaching the properties of inorganic glass by reducing the water content, and has a property of flowing with a reduced viscosity by increasing the water content.

  Therefore, the sand core formed by binding with the binder containing water glass has sufficient strength at the time of casting. On the other hand, at the time of discharging from the cast molding coarse material, by giving moisture, the binding force by the water glass is weakened and the strength of the sand core is reduced, and the impact force is applied to the cast molding crude material with a weak impact force. The sand core can be destroyed without being added, and can be easily discharged.

  The core discharge device of the present invention includes a humidified gas supply device that supplies a humidified humidified gas to which humidity has been added. If necessary, a recovery device that collects the humidified gas, a striking device, It has a vibration device and the like.

<Humidified gas supply device>
The humidifying gas supply device supplies humidified humidified gas to the sand core in the cast molded product, and includes a humidifying device and a blower, and if necessary, removes droplets. A device and a supply nozzle are provided.

  As the humidifier, a steam type that boiles water to generate steam, an ultrasonic type that blows water into fine particles as it is, a hybrid type that combines these, a porous body containing water, and a gas into water Any of vaporization type may be used, but ultrasonic type is preferable from the viewpoint of thermal efficiency.

In casting, exhaust heat can be used, and high-temperature gas can be used.
Therefore, when the humidifier is an ultrasonic type, it is possible to efficiently humidify the water by bringing the water mist into contact with the high temperature gas, and the high temperature humidified gas is cooled to a desired temperature by the water mist. Thus, water vapor in the humidified gas can be saturated.

  The air blower may be any type such as a fan or blower as long as the humidified gas can be supplied to the sand core, but preferably has a large pressure ratio.

  By increasing the wind speed of the humidified gas, it is possible to blow away the cast sand whose binding power by the water glass is weakened and to reach the inside of the sand core. In addition, it is not necessary to provide a blower in the collection path of the collection device for collecting high-temperature gas, which will be described later, and failure of the blower due to heat can be prevented.

  The humidified gas supply device preferably includes a droplet removing device. If the humidified gas contains liquid droplets, a liquid film may be formed near the surface of the sand core, making it difficult for the humidified gas to reach the inside of the sand core. Before supplying the humidified gas to the sand core, the humidified gas permeates into the sand core by removing the droplets, reducing the strength not only on the surface of the sand core but also inside the sand core. And the sand core can be destroyed quickly.

An example of the droplet removing device is a demister. The demister is composed of a knit mesh formed of metal or resin.
When the humidified gas passes through the demister accompanied by fine droplets, the humidified gas itself passes through the gap of the knitted mesh, but the droplet contacts the surface of the mesh wire. Then, the droplet temporarily stays on the wire due to the wettability of the wire and the capillary phenomenon, but the droplet diameter gradually increases due to the surface tension, and the droplet is removed by dropping from the wire due to the weight of the droplet. The

The humidified gas supply device preferably includes a supply nozzle. By supplying the humidified gas using the supply nozzle, the flow rate, flow rate, direction, pressure, etc. of the humidified gas can be adjusted.
And the self-disintegration and removal of a sand core are accelerated | stimulated by directing a supply nozzle to the sand discharge port direction of a cast molding coarse material, and supplying the humidification gas which made the flow velocity quick.

  The amount of moisture contained in the humidified gas supplied by the humidified gas supply device depends on the temperature of the humidified gas to be supplied, but is preferably close to the saturated water vapor amount at the time of supply, and the relative humidity is 80% or more. It is preferable.

In addition, the amount of water vapor that can be contained in air is limited, and the saturated water vapor amount increases as the temperature increases. Therefore, it is preferable that the temperature of the humidified gas is high from the viewpoint of water supply.
However, the present invention also adjusts the cooling rate of the cast molded product coarse material and quenches the cast molded product coarse material, and the temperature of the humidified gas supplied from the balance between the two is 40 ° C to 100 ° C. It is preferable and it is more preferable that it is 60 to 80 degreeC.

<Recovery device>
The recovery device recovers the humidified gas supplied to the cast molded product coarse material. Specifically, the recovery device recovers the high-temperature gas heated by the cast molded product crude material, and supplies the humidified gas. It supplies to the device.
The recovery device includes a chamber, piping for connecting the chamber and the humidifier, and the like.

The chamber covers a processing booth that supplies humidified gas to the cast material rough material. By supplying the humidified gas while covering the processing booth in the chamber, the high-temperature gas heated by the cast molding crude material is supplied to the humidified gas supply device through the pipe.
By rehumidifying and cooling the collected high-temperature humidified gas again, the water vapor in the humidified gas can be saturated.

<Blow device>
The hitting device applies an impact force to the cast material coarse material to break the sand core, and an air hammer or the like can be used. In the present invention, in addition to the strength of the sand core being reduced by the humidified gas, the cast molded material coarse material is cooled by the humidified gas and contracts, and the sand core is compressed and further easily destroyed. Become.
Therefore, it is possible to reduce the impact force applied to the cast molding coarse material, to reduce the time and number of times of hitting, to prevent the cast molded product from being deformed or broken by the impact force, and to the impact device. Maintenance costs can be reduced.

<Excitation device>
The vibration device vibrates the cast molded product coarse material and discharges the broken sand core from the sand discharge port of the cast molded product coarse material, and can be any of mechanical, hydraulic, and electrodynamic types. There may be.

  Hereinafter, the present invention will be described in detail by embodiments, but the present invention is not limited to the following embodiments.

  A sand core formed with a binder containing water glass is placed in a mold, and a molten metal is supplied into the mold. When the molten metal is solidified, the cast product coarse material 1 is taken out of the mold, and the cast product coarse material 1 is placed in the processing booth 2 for discharging the core. At this time, the temperature of the cast material coarse material is about 350 ° C to 500 ° C.

As shown in FIG. 1, the processing booth 2 is covered with a chamber 3, and a humidified gas 4 is supplied to the cast molded product rough material 1 in the chamber 3 to reduce the strength of the sand core 5. .
A plurality of cast molded product coarse materials 1 may be placed in the processing booth 2 and the humidified gas 4 may be supplied to a plurality of units in parallel. Since the amount of water vapor contained in the humidified gas 4 is limited, it may take time until the strength of the sand core 5 is sufficiently reduced. By simultaneously treating a plurality of units, the sand core 5 is efficiently discharged. can do.

  The humidified gas 4 is generated by the humidifier 7 of the humidified gas supply device 6. The humidifier 7 sprays a mist 9 of water into the supplied high-temperature air 8 to humidify the high-temperature air 8 and cool it to 40 ° C. to 100 ° C. Water droplets are removed from the cooled humidified gas 4 through the demister 10. After that, kinetic energy is given by the blower 11 and is supplied to the cast molded product rough material 1 in the processing booth 2 through the supply nozzle 12.

  The humidified gas 4 supplied to the cast molded product coarse material 1 is heated by the cast molded product coarse material 1 while supplying moisture to the sand core 5 to reduce the strength. The heated high-temperature air 8 is supplied to the humidifying device 7 of the humidifying gas supply device 6 by the recovery device 13, humidified again, and supplied to the cast molded product rough material 1.

  The sand core 5 is supplied with moisture by the humidified gas 4 and decreases in strength. In addition, since the cast product coarse material 1 is cooled to a temperature at which an impact force can be applied, the impact force can be applied quickly by a striking device (not shown). The destroyed sand core 5 is discharged from the cast molded product rough material 1 by vibration by a vibration device (not shown).

The core discharging apparatus and the core discharging method of the present invention can be suitably used for a cast product having a thin mouth and a complicated shape, such as an aluminum alloy cylinder head.

DESCRIPTION OF SYMBOLS 1 Cast molding raw material 2 Processing booth 3 Chamber 4 Humidification gas 5 Sand core 6 Humidification gas supply device 7 Humidification device 8 High temperature air 9 Mist 10 Demister 11 Blower device 12 Supply nozzle 13 Recovery device

Claims (8)

A core discharge device for discharging the core from the cast material rough material,
The core is a sand core containing a binder containing water glass,
A core discharge device comprising a humidified gas supply device for supplying a humidified gas with humidity added to a sand core in the cast product.   The core discharging apparatus according to claim 1, wherein the temperature of the humidified gas is 40 ° C to 100 ° C.   The core discharging apparatus according to claim 1 or 2, wherein the humidified gas is a gas from which droplets are removed.   The core discharging apparatus according to any one of claims 1 to 3, further comprising a recovery device that recovers the humidified gas supplied to the sand core and supplies the humidified gas to the humidified gas supply device. A core discharging method for discharging a core from a cast material rough material,
The core is a sand core containing a binder containing water glass,
A core discharge method comprising a humidified gas supply step of supplying a humidified gas in which humidity is added to a sand core in the cast molded product.   The core discharging method according to claim 5, wherein the temperature of the humidified gas is 40 ° C. to 100 ° C.   The core discharging method according to claim 5 or 6, further comprising a droplet removing step of removing droplets from the humidified gas before supplying the humidified gas.   It has a recovery process of recovering the humidified gas supplied to the sand core, and uses the humidified gas recovered in the humidified gas supply step. The core discharging method described in the paragraph.

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